Russian Defense Minister Gen. Sergei Shoigu said Wednesday that Russia and China will hold major war games similar to the ongoing Vostok 2018 exercises on a "regular basis."

The Department of Defense said Monday that it is closely watching the ongoing drills — the largest Russian war games in decades.

Big Russia-China war games are apparently going to be routine going forward, the Russian defense minister revealed Wednesday.

"We have agreed to conduct such exercises on a regular basis," General Sergei Shoigu stated Wednesday as he toured the Tsugol firing range in eastern Siberia where thousands of Russian and Chinese troops are training together for war. The defense minister was accompanied by Chinese General Wei Fenghe at the time of the announcement, which comes as both Russia and China confront the US.

During Wednesday's exercises, Russian strategic bombers launched long-range cruise missiles at a firing range while warships opened fire on targets at sea, the Associated Press reported. There are at least 300,000 Russian troops, 36,000 vehicles, and 1,000 aircraft taking part in the Vostok 2018 exercises, the largest Russian war games in decades, CNN reported, citing the Russian Ministry of Defense.

Shoigu said previously that the drills were being held on an "unprecedented scale both in territory and number of troops involved." China deployed 900 combat vehicles and 30 aircraft, along with 3,200 troops, to the drills. Mongolia also sent troops to participate.

The strengthening of military ties between Russia and China is particularly alarming given rising tensions between each country and Washington.

China has grown bolder in the South China Sea, deploying advanced weapons platforms to the disputed waterway and challenging foreign ships and planes that fly or sail too close to territorial holdings occupied by China while Beijing argues with Washington over everything from trade to North Korea. Russia, on the other hand, has gone so far as to threaten to conduct strikes on a key US-led coalition base in Syria and fly strategic bombers near Alaska, risky moves amid deteriorating relations between Russia and the US.

Pentagon spokesman Col. Rob Manning said Monday that the US respects Russia and China's decision to hold military exercises, something the US also does with its allies and international partners. He added, though, that the US is watching these exercises closely.